> is there a modification to the regex to not include the surrounding
 quotes?

 <xsl:variable name="regex">
     <xsl:text>\s*"(([^"]*)"|([^,]+))\s*</xsl:text>
   </xsl:variable>

then use
<xsl:value-of select="concat(regex-group(2),regex-group(3))"/>

Only one of the groups will be non-empty, but concating them together is
probably easier than testing which group you need.

David